Commit 7691ba06 authored by Linus Walleij's avatar Linus Walleij Committed by Bartosz Golaszewski
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gpio: Further document optional GPIOLIB 



Optional GPIOLIB as in not depended on or selected by a driver
should NOT use any *_optional() calls, this becomes paradoxical.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent e404b0cc

Documentation/driver-api/gpio/consumer.rst

+4 −0
Original line number Diff line number Diff line
@@ -29,6 +29,10 @@ warnings. These stubs are used for two use cases: 
  will use it under other compile-time configurations. In this case the

  consumer must make sure not to call into these functions, or the user will

  be met with console warnings that may be perceived as intimidating.

  Combining truly optional GPIOLIB usage with calls to

  ``[devm_]gpiod_get_optional()`` is a *bad idea*, and will result in weird

  error messages. Use the ordinary getter functions with optional GPIOLIB:

  some open coding of error handling should be expected when you do this.



All the functions that work with the descriptor-based GPIO interface are

prefixed with ``gpiod_``. The ``gpio_`` prefix is used for the legacy